Clenbuterol toxicity: a NSW Poisons Information Centre experience

March 6, 2014

Med J Aust 2014; 200 (4): 219-221.

doi:10.5694/mja13.10982

Authors: Jonathan Brett, Andrew H Dawson, Jared A Brown

Clenbuterol is a β2-adrenergic agonist with a long half-life of around 25–40 hours and high bioavailability,1 currently registered in Australia as a Schedule 4 medicine for veterinary use.2 It is marketed in tablet, gel and injectable forms as an equine bronchodilator and a bovine tocolytic agent. Its anabolic properties have seen it used in food-producing animals to increase lean meat yield.3 However, concerns about toxicity to humans from contaminated meat led to its use for this purpose being banned in the United States in 1991 and the European Union in 1996. Since then, there have been outbreaks of clenbuterol toxicity from contaminated meat across Europe and China,4–6 and outbreaks of clenbuterol contamination of heroin.7

The spectrum of toxicity in humans includes sympathomimetic effects such as restlessness, tachycardia and tachyarrhythmias,8 gastrointestinal disturbances and rhabdomyolysis, and metabolic disturbances such as hyperglycaemia and hypokalaemia. There have also been case reports of myocardial ischaemia…